For its high precision, tracer determination method is popular in nuclear power plants, but there are several adverse aspects such as complicated operating process, intricate Selleckchem SCH772984 data processing, and costly instruments [9, 10]. Therefore, up to now, online measurement of Epacadostat clinical trial wetness in steam turbines as accessibility is still a major challenge. Methods In this paper, we consider the use of surface plasmon resonance (SPR) for measuring steam wetness. Surface plasmon (SP) waves have been studied since the 1960s. They can be described as a collective oscillation in electron density at the interface of metal and dielectric. Resonance occurs when the wave vector of surface plasmon wave equals
to the tangential component of evanescent wave vector (i.e., the phase-matching condition) under appropriate incident conditions (e.g., incident angle and wavelength). Under SPR, the incident light will be strongly absorbed, showing a deep reflection dip. Since a stringent phase-matching condition is needed, SPR is very sensitive to the system configuration and surrounding environment, which allows using this unique property for measuring steam wetness. According to the dielectric theory, at room temperature, the relative dielectric constant of saturated water vapor is close to that of air. Therefore, find more the wet steam is modeled by spraying atomized water
on the hydrophobic coating layer of the Kretschmann configuration with the designed two-phase nozzle in the experiments. The steam wetness is regulated through the spraying quantity, and the absolute wetness X is given by [1, 2, 8] where ∅ w(ρ w) and ∅ g(ρ g) are the volume ratios (densities) of spraying water and air flow, respectively. Assuming a constant transverse (parallel to the metal-dielectric interface) droplet distribution, Equation 1 can be simplified as where S w and S g are the area ratio of water and air on SPR surface,
respectively. Here, S w and S g can be measured by SPR. A schematic of the steam wetness measurement system is displayed in Figure 1, which is composed mainly of transmitter, measuring space, and receiver: 1. The transmitter MycoClean Mycoplasma Removal Kit unit is configured to convert the light source into a parallel light beam with transverse magnetic polarization (i.e., the magnetic field direction parallel to the metal/prism surface in Kretschmann configuration). It comprises the DH-2000 Deuterium Tungsten Halogen Light Source (Ocean Optics, Dunedin, FL, USA), optical fiber, lens, and polarizer. 2. The core component of measuring space is the Kretschmann configuration, also referred to as attenuated total reflection, in which a 45-nm Au layer is evaporated on top of a SF2 prism. In order to prevent water coating, a 2- to 3-nm ultrathin layer of hydrophobic thiol coating is formed on the surface of the Au layer. In our experiments, the special container on top of the Kretschmann configuration is designed to hold water. 3.